Investigating the performance of a roller footgear in the offshore shrimp fishery of Eastern Canada using underwater video

The offshore Northern shrimp (Pandalus borealis) fishery in Eastern Canada is currently harvested by factory freezer vessels using bottom trawls. This fishery is a major contributor to the regions' economy, however, bottom trawling typically is associated with negative benthic impacts. We evaluated the at-sea engineering performance of a roller footgear using underwater cameras. This footgear is designed to roll, limiting negative benthic impacts and reducing fuel usage, compared to non-rolling rockhopper footgear. We describe and document a new technique for measuring the time to complete a rotation in seconds (TCR) of bosom and quarter-wing footgear sections on hard, mixed, and soft seabed. Our results showed that footgear sections were rotating at extremely low rates. Results predicted a statistically significant 184 % increase in TCR when comparing the bosom to the quarter-wing section (p = 0.035). TCR on hard seabed ranged from 23.6 s in the bosom to 43.4 s in the quarterwing section, while mixed (from 169.0-311.1 s) and soft (from 862.6-1587.6 s) seabed types produced significantly longer TCR (p < 0.001). This study provides evidence that roller footgear is not rotating at the velocity expected by the industry and offers essential information to further develop innovative footgear with reduced seabed impact.

Automated summary

This study evaluated the performance of roller footgear in reducing negative benthic impacts and fuel usage compared to non-rolling rockhopper footgear in the Northern shrimp fishery. Results showed that footgear sections rotated at low rates, with significantly longer rotation times on mixed and soft seabeds compared to hard seabeds. The findings suggest that roller footgear may not be rotating as quickly as expected, providing valuable insights for further development of innovative footgear to minimize seabed impact.